Fokker-Planck Coefficients for Coulomb Scattering

This page contains libraries of coefficients for electron-electron and electron-proton Coulomb scattering (the corresponding publication is Finke & Böttcher 2005). These coefficients are used in a Fokker-Planck equation which describes the evolution of electrons in a very hot, fully-ionized plasma. For an isotropic and homogeneous particle distribution the Fokker-Planck equation has the form

Each library file, whether the scattering is incident on electrons or protons, contains three columns. The first is the kinetic energy of the incident electron in terms of the Lorentz factor, γ. The second column contains the energy exchange coefficient, and the third the dispersion coefficient. The coefficients were calculated for small-angle scattering approximations using formulae found in Nayakshin and Melia (1998). The files have been tarred and gnu-zipped, so that each is about six MB. When unzipped, they will occupy about forty MB each.

Library for electron-electron scattering: dge.tar.gz
Each file will have a name corresponding to the electron temperature of the plasma in keV (e.g., dge0148.dat corresponds to an electron temperature of 148 keV).

Libraries for electron-proton scattering: dgp0.tar.gz
                                                                   dgp1.tar.gz
                                                                   dgp2.tar.gz
                                                                   dgp3.tar.gz
                                                                   dgp4.tar.gz
                                                                   dgp5.tar.gz
                                                                   dgp6.tar.gz
                                                                   dgp7.tar.gz
                                                                   dgp8.tar.gz
                                                                   dgp9.tar.gz
When untarred and unzipped, these libraries will consist of numerous files with a name corresponding to the proton temperature of the plasma, in tens of keV (e.g., dgp5466.dat for a proton temperature of 54.660 MeV). In the case of proton temperatures greater than or equal to 100 MeV the "p" is replaced by the first digit symbolizing the proton temperature (e.g., dg17899.dat contains data for scattering in a plasma with a proton temperature of 178.990 MeV).   

Please e-mail any questions to Justin Finke.